Cancer stem cell markers in locally advanced breast cancer.

1075 Background: the expressions of CD44/CD24, CXCR4 and ABCG2 have been reported as potential breast cancer stem-like cell (CSLC) markers. The association between the quantity of CSLCs and the response to neoadjuvant chemotherapy (NACT) remains unclear. Methods: we prospectively analyzed the expression of CD44/CD24, CXCR4 and ABCG2 in 20 patients with locally advanced or metastatic (LAMBC) invasive ductal carcinomas of the breast subjected to NACT. The mammosphere assay (Mammocult) was studied in 10 samples. Patients’ mean age was 55.6 ± 8.2 yo. According to clinical stage (CS), 5 patients were IIb, 4 - IIIa, 8 - IIIb and 3 - IV. The mean clinical tumor diameter was 6.3 ± 2.8cm. The ER, PgR and HER2 positive expression rates were 50%, 45% and 50%, respectively. Ten patients were treated with EC-T, eight were treated with EC-TH (HER2+) and two were treated with FEC75 combination as NACT. The median percentage CD44+/CD24-, CXCR4+, ABCG2+ and ESA+ cells within Lin- cells were determined by flow cytometry in...